An international team of astronomers has discovered an exotic young planet that is not orbiting a star. This free-floating planet, dubbed PSO J318.5-22, is just 80 light-years away from Earth and has a mass only six times that of Jupiter. The planet formed a mere 12 million years ago—a newborn in planet lifetimes.
It was identified from its faint and unique heat signature by the Pan-STARRS 1 (PS1) wide-field survey telescope on Haleakala, Maui. Follow-up observations using other telescopes in Hawaii show that it has properties similar to those of gas-giant planets found orbiting around young stars. And yet PSO J318.5-22 is all by itself, without a host star.